This chart shows past emission trends of nitrogen oxides (NOx), non-methane volatile organic compunds (NMVOC), carbon monoxide (CO) and methane (CH4) in the EEA-32 and EU-27 group of countries. In addition - for the EU-27 - the aggregated Member State 2010 and 2020 emission ceilings for NOx and NMVOC are shown.

In the air quality directive (2008/EC/50), the EU has set a target value and a long term objective value for ozone (O3) for the protection of vegetation. Target value: the AOT40 may not exceed 18000 (µg/m3) per hour in the period from 1 May to 31 July averaged over five years. Long term objective value: the AOT40 may not exceed 6000 (µg/m3) per hour in the period from 1 May to 31 July within a calendar year.
AOT40 (expressed in (μg/m3) ∙ hours) means the sum of the difference between hourly concentrations greater than
80 μg/m3 (= 40 parts per billion) and 80 μg/m3 over a given period using only the one-hour values measured
between 8.00 and 20.00 Central European Time (CET) each day. More information is provided in Annex VII of directive (2008/EC/50).

In the air quality directive (2008/EC/50), the EU has set a target value and a long term objective value for ozone (O3) for the protection of human health. Target value: the maximum daily eight-hour mean may not exceed 120 micrograms per cubic metre (µg/m3) on more than 25 days per calendar year averaged over three years. Long term objective value: the maximum daily eight-hour mean may not exceed 120 micrograms per cubic metre (µg/m3) within a calendar year.

The total production and consumption of ozone depleting substances in EEA member countries has decreased significantly since the Montreal Protocol was signed in 1987 - nowadays it is practically zero. Globally, the implementation of the Montreal Protocol has led to a decrease in the atmospheric burden of ozone-depleting substances (ODSs) in the lower atmosphere and in the stratosphere.
Many of the ODS are also potent greenhouse gases in their own right, but as they are governed through the Montreal Protocol, they are not separately regulated under the UN Framework Convention on Climate Change (UNFCCC). Thus the phasing out of ODS under the Montreal Protocol has also avoided global greenhouse gas emissions. In 2010, it has been estimated that the reduction of greenhouse gas emissions achieved under the Montreal Protocol was 5 to 6 times larger than that which will result from the UNFCCC's Kyoto Protocol first commitment period, 2008-2012.